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Old 11-26-11, 01:46 PM   #1
michaelnel
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High Effort

I am finding that riding my Dahon D7HG requires significantly higher effort from me than riding my 700c full-size bike.

It isn't the weight, if anything my full sized bike weighs more.

It isn't brake drag, I have checked repeatedly that the v-brakes are centering right and not rubbing at all.

Chain is adjusted so there is just a little (1/2" or so) slack in it at the tightest point.

Tires are aired up to 65PSI.

When I spin the front wheel with the bike up on the service stand it seems to rotate a LONG time. The rear, not so much. Seems like there is a lot of friction in the Nexus hub.

But when I ride the same route on the 700c bike as on the 20" Dahon, I notice I get to coast a lot more. On the Dahon, it seems like I always have to be pedaling. Anyone else notice this when riding a folder vs a full sized bike?
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Old 11-26-11, 02:50 PM   #2
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Originally Posted by michaelnel View Post
I am finding that riding my Dahon D7HG requires significantly higher effort from me than riding my 700c full-size bike.


Tires are aired up to 65PSI.

When I spin the front wheel with the bike up on the service stand it seems to rotate a LONG time. The rear, not so much. Seems like there is a lot of friction in the Nexus hub.

But when I ride the same route on the 700c bike as on the 20" Dahon, I notice I get to coast a lot more. On the Dahon, it seems like I always have to be pedaling. Anyone else notice this when riding a folder vs a full sized bike?
Depends on the bike ... and on your riding posture .. is your 700c bike set up to be a 'sit up and beg' riding style also? .. tires will make a difference if you are talking about wide, low pressure 406 vs. high pressure, narrow 700c tires.. I find that on my Moulton with high pressure 406x1.25 slicks, I generally 'out coast' most all of the riders I routinely ride with on their variety of high end 700c road bikes... the mechanical pedaling inefficiency of the Shimano Nexus 7 is going to be apparent compared to a clean well tuned derailleur system .. Using the same frame and rider position, I'm noticeably faster on my derailleur equipped bikes over the same routes than I am with my IGH gear bikes with more than 5 gears in the can ..
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Old 11-26-11, 03:09 PM   #3
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the mechanical pedaling inefficiency of the Shimano Nexus 7 is going to be apparent compared to a clean well tuned derailleur system .. Using the same frame and rider position, I'm noticeably faster on my derailleur equipped bikes over the same routes than I am with my IGH gear bikes with more than 5 gears in the can ..
That's why I chose the Bike Friday over an IGH mod to my Dahon Speed D7. I wanted super-low climbing gears and efficiency.
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Old 11-26-11, 03:16 PM   #4
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Originally Posted by michaelnel View Post
But when I ride the same route on the 700c bike as on the 20" Dahon, I notice I get to coast a lot more. On the Dahon, it seems like I always have to be pedaling. Anyone else notice this when riding a folder vs a full sized bike?
Don't really notice this on my Bike Friday (20" wheels), but I inflate the tires to 100+ psi. I do notice that the Bike Friday is more affected by lower tire pressure. If I let the tires on my 700c bike drop to 70psi it makes them more susceptible to pinch flats but the rolling resistance only increases a little. The same pressure in my 20" wheels results in a substantial increase in rolling resistance. My bikes are all derailleur gearing - no IGH.
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Old 11-26-11, 04:05 PM   #5
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Definitely - I estimate that my slower folder (Downtube Mini with IGH) was about 10% or more slower than my Swift, which itself is indistinguishable from a roadie.
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Old 11-26-11, 08:08 PM   #6
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My constant go to bike is a Downtube 8H with the Sturmey Archer 8 speed.
Just sooooooo convenient.
Always fun to ride. Easy to store out of the way.
But!! I'm always amazed when I get on my old Fuji, it is so much easier to ride.
Actually seems to glide compared to the 8H.
With the 8H I'm constantly shifting, with the Fuji I may go all day in the same gear.
Oh well, I like one but love the other.
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Old 11-27-11, 03:51 AM   #7
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are the tires stock with the dahon logo?
They're quite supple, but for some reason, they don't exactly offer low rolling resistance.
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Old 11-27-11, 07:57 AM   #8
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I'm interested in this issue too. Having been riding the same IGH on a few bikes I had a go on a friends Mu P8 and immediately felt like it was coasting with significantly less resistance. I re-serviced my SA hubs with the aim of making sure the cones were optimally adjusted and performance was noticeably improved. I've ridden the Mu P8 again since and the difference wasn't particularly obvious, but it'd require more riding to get a clearer sense. The Mu P8 shifted extremely cleanly too; I'm not so sure I'd opt for an IGH on a 20" bike now.
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Old 11-27-11, 08:22 AM   #9
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Depends on the bike ... and on your riding posture .. is your 700c bike set up to be a 'sit up and beg' riding style also?
Pretty much. The handlebars are about level with the saddle.

Quote:
tires will make a difference if you are talking about wide, low pressure 406 vs. high pressure, narrow 700c tires
Yes, I realize that, but I am running Panaracer Pasela TourGuard 700x35c tires on the SOMA. Not high pressure or narrow.

Quote:
I find that on my Moulton with high pressure 406x1.25 slicks, I generally 'out coast' most all of the riders I routinely ride with on their variety of high end 700c road bikes... the mechanical pedaling inefficiency of the Shimano Nexus 7 is going to be apparent compared to a clean well tuned derailleur system .. Using the same frame and rider position, I'm noticeably faster on my derailleur equipped bikes over the same routes than I am with my IGH gear bikes with more than 5 gears in the can ..
I am thinking maybe to try Schwalbe Kojaks on it.
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Old 11-27-11, 08:25 AM   #10
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are the tires stock with the dahon logo?
They're quite supple, but for some reason, they don't exactly offer low rolling resistance.
Yes, it has the stock Dahon Rotolos on it. They are likely cheap and nasty tires, but they look cool. I think I will try a set of Schwalbe Kojaks. I have a VO saddle with springs so I don't think I really need the extra cushion of Big Apples, and the BAs even in their narrowest width are still wider than my fenders.
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Old 11-27-11, 08:28 AM   #11
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I'm not so sure I'd opt for an IGH on a 20" bike now.
I don't think I would either. I have never had any problems with derailleur-equipped bikes (I am a pretty good mechanic and keep them well lubed, cleaned, and adjusted), so I think I would go that route if I had it to do over again.
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Old 11-27-11, 01:19 PM   #12
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Tires are aired up to 65PSI.
Try some Tires rated for 100 psi and pump them up
to that, and keep it there, and see how that goes.

centripetal mass of the bigger wheel also works against you in acceleration .

so keep that in mind., that's just newtonian laws of physics.
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Old 12-10-11, 02:52 PM   #13
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So you've sold the bike already, michaelnel?
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Old 12-10-11, 03:47 PM   #14
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Yes, I sold the bike.
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